diff --git a/flake.lock b/flake.lock
index 90fa19e89..1579b7e68 100644
--- a/flake.lock
+++ b/flake.lock
@@ -5,11 +5,11 @@
         "nixpkgs-lib": "nixpkgs-lib"
       },
       "locked": {
-        "lastModified": 1701473968,
-        "narHash": "sha256-YcVE5emp1qQ8ieHUnxt1wCZCC3ZfAS+SRRWZ2TMda7E=",
+        "lastModified": 1709336216,
+        "narHash": "sha256-Dt/wOWeW6Sqm11Yh+2+t0dfEWxoMxGBvv3JpIocFl9E=",
         "owner": "hercules-ci",
         "repo": "flake-parts",
-        "rev": "34fed993f1674c8d06d58b37ce1e0fe5eebcb9f5",
+        "rev": "f7b3c975cf067e56e7cda6cb098ebe3fb4d74ca2",
         "type": "github"
       },
       "original": {
@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1703134684,
-        "narHash": "sha256-SQmng1EnBFLzS7WSRyPM9HgmZP2kLJcPAz+Ug/nug6o=",
+        "lastModified": 1710097495,
+        "narHash": "sha256-B7Ea7q7hU7SE8wOPJ9oXEBjvB89yl2csaLjf5v/7jr8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d6863cbcbbb80e71cecfc03356db1cda38919523",
+        "rev": "d40e866b1f98698d454dad8f592fe7616ff705a4",
         "type": "github"
       },
       "original": {
@@ -37,11 +37,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1701253981,
-        "narHash": "sha256-ztaDIyZ7HrTAfEEUt9AtTDNoCYxUdSd6NrRHaYOIxtk=",
+        "lastModified": 1709237383,
+        "narHash": "sha256-cy6ArO4k5qTx+l5o+0mL9f5fa86tYUX3ozE1S+Txlds=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "e92039b55bcd58469325ded85d4f58dd5a4eaf58",
+        "rev": "1536926ef5621b09bba54035ae2bb6d806d72ac8",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 8f210ab4a..b28a54ce1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -12,7 +12,7 @@
     perSystem = { config, self', inputs', pkgs, system, ... }:
       with pkgs;
       let
-        nix = nixVersions.nix_2_16;
+        nix = nixVersions.nix_2_19;
         llvmPackages = llvmPackages_16;
         nixd = callPackage ./default.nix {
           inherit nix;
diff --git a/libnixt/lib/Deserialize.cpp b/libnixt/lib/Deserialize.cpp
index 6cd9b771e..7225dc2ad 100644
--- a/libnixt/lib/Deserialize.cpp
+++ b/libnixt/lib/Deserialize.cpp
@@ -46,10 +46,6 @@ class ASTDecoder {
     return create<nix::ExprString>(eat<std::string>());
   }
 
-  nix::ExprPath *decodeExprPath() {
-    return create<nix::ExprPath>(eat<nix::Path>());
-  }
-
   nix::ExprVar *decodeExprVar() {
     auto Pos = decodePosIdx();
     auto Name = decodeSymbol();
@@ -76,8 +72,6 @@ class ASTDecoder {
       return decodeExprFloat();
     case EncodeKind::ExprString:
       return decodeExprString();
-    case EncodeKind::ExprPath:
-      return decodeExprPath();
     case EncodeKind::ExprVar:
       return decodeExprVar();
     default:
@@ -112,9 +106,6 @@ template <> nix::Pos::Origin consume<nix::Pos::Origin>(BytesRef &Data) {
   case 2:
     return nix::Pos::Stdin{nix::make_ref<std::string>("")};
     break;
-  case 3:
-    return nix::CanonPath(consume<std::string>(Data));
-    break;
   default:
     assert(false && "Unknown origin");
     break;
diff --git a/libnixt/lib/Serialize.cpp b/libnixt/lib/Serialize.cpp
index d9fd2d55c..23846fe8b 100644
--- a/libnixt/lib/Serialize.cpp
+++ b/libnixt/lib/Serialize.cpp
@@ -33,13 +33,13 @@ class ASTEncoder {
   void encodeExprInt(const nix::ExprInt *E) {
     assert(E);
     ExprMap[E] = encode(OS, EncodeKind::ExprInt);
-    encode(OS, E->n);
+    encode(OS, E->v.integer);
   }
 
   void encodeExprFloat(const nix::ExprFloat *E) {
     assert(E);
     ExprMap[E] = encode(OS, EncodeKind::ExprFloat);
-    encode(OS, E->nf);
+    encode(OS, E->v.fpoint);
   }
 
   void encodeExprString(const nix::ExprString *E) {
diff --git a/libnixt/test/Deserialize.cpp b/libnixt/test/Deserialize.cpp
index 96dd6d0a3..d37c8a30d 100644
--- a/libnixt/test/Deserialize.cpp
+++ b/libnixt/test/Deserialize.cpp
@@ -44,14 +44,14 @@ void checkEmpty(BytesRef &Data) { EXPECT_EQ(lengthof(Data), 0); }
 TEST_F(DeserializeTest, ExprInt) {
   auto Data = encode(mkInt(0xdeadbeef).get());
   auto *E = consumeAST(Data, Pool, PT, ST);
-  EXPECT_EQ(static_cast<nix::ExprInt *>(E)->n, 0xdeadbeef);
+  EXPECT_EQ(static_cast<nix::ExprInt *>(E)->v.integer, 0xdeadbeef);
   checkEmpty(Data);
 }
 
 TEST_F(DeserializeTest, ExprFloat) {
   auto Data = encode(new nix::ExprFloat{3.14});
   auto *E = consumeAST(Data, Pool, PT, ST);
-  EXPECT_EQ(static_cast<nix::ExprFloat *>(E)->nf, 3.14);
+  EXPECT_EQ(static_cast<nix::ExprFloat *>(E)->v.fpoint, 3.14);
   checkEmpty(Data);
 }
 
@@ -62,13 +62,6 @@ TEST_F(DeserializeTest, ExprString) {
   checkEmpty(Data);
 }
 
-TEST_F(DeserializeTest, ExprPath) {
-  auto Data = encode(new nix::ExprPath{"hello"});
-  auto *E = consumeAST(Data, Pool, PT, ST);
-  EXPECT_EQ(static_cast<nix::ExprPath *>(E)->s, "hello"s);
-  checkEmpty(Data);
-}
-
 TEST_F(DeserializeTest, ExprVar) {
   auto EV = std::make_unique<nix::ExprVar>(somePos(), ST.create("hello"));
   EV->level = 43;
diff --git a/libnixt/test/Serialize.cpp b/libnixt/test/Serialize.cpp
index 987e682c7..6567aca11 100644
--- a/libnixt/test/Serialize.cpp
+++ b/libnixt/test/Serialize.cpp
@@ -85,13 +85,6 @@ TEST_F(SerializeTest, Origin_String) {
   checkEmpty(Data);
 }
 
-TEST_F(SerializeTest, Origin_Path) {
-  auto Data = encode(nix::CanonPath("/"));
-  check(Data, (std::size_t)3);
-  check(Data, "/"s);
-  checkEmpty(Data);
-}
-
 TEST_F(SerializeTest, ExprInt) {
   auto Data = encode(mkInt(0xdeadbeef).get());
   checkASTHeader(Data);
@@ -126,16 +119,6 @@ TEST_F(SerializeTest, ExprString) {
   checkEmpty(Data);
 }
 
-TEST_F(SerializeTest, ExprPath) {
-  auto EP = std::make_unique<nix::ExprPath>(nix::Path{"hello"});
-  auto Data = encode(EP.get());
-  checkASTHeader(Data);
-  checkTrivialOrigin(Data);
-  check(Data, EncodeKind::ExprPath);
-  check(Data, "hello"s);
-  checkEmpty(Data);
-}
-
 TEST_F(SerializeTest, ExprVar) {
   auto EV = std::make_unique<nix::ExprVar>(somePos(), ST.create("hello"));
   EV->level = 43;